1. Field of the Invention
The present invention relates to a fuel hose for transportation or the like of fuel for automobiles and the like such as gasoline, alcohol-containing gasoline, diesel fuel, RME (fatty acid methyl ester)-containing diesel fuel, GTL (Gas to Liquid)-containing diesel fuel, CNG (Compressed Natural Gas) or LPG (Liquefied Petroleum Gas).
2. Description of the Art
With growing worldwide awareness of environmental issues, the control of the amount of fuel permeation from an automotive fuel hose and the like has been enhanced. Particularly in North America, stringent regulations against fuel permeation are recently coming into effect. Under such a situation, a fuel hose has been proposed which includes a three-layer structure having an inner layer composed of acrylonitrile-butadiene rubber (NBR), an intermediate layer composed of a tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer (THV) and an outer layer composed of NBR-PVC, or which includes a four-layer structure having the same inner layer, the same intermediate layer, an outer layer composed of NBR and an outermost layer composed of chlorosulfonated polyethylene rubber (CSM).
However, the layer including NBR does not adhere well to the layer made of THV. Therefore, a fuel hose having improved interlaminar adhesion between the layer including NBR and the layer made of THV by adding 1,8-diazabicyclo[5.4.0]undecene-7 salt (DBU salt) into the layer including NBR has been proposed (see Japanese Unexamined Patent Publication No. 8-169085 (1996)).
Such a countermeasure is effective for the case where the above-mentioned ternary THV is used. However, in the case where a quaternary THV, excellent in craze resistance and fuel permeation resistance, is used, the layer including NBR does not adhere well to the layer made of THV, even if DBU salt is added to the layer including NBR.
In view of the foregoing, it is an object of the present invention to provide a fuel hose excellent in fuel permeation resistance and interlaminar adhesion.